Improvement in steam-engines



taai-'tir A iatra aan e caa contraction of the cylinder-casting in cooling.

THOMAS ROSS, OF RTLAND, VERMONT.

Letters Patent No. 110,681, dated January 3, 1871.

IMPROVEMENT IN STEAM-ENGINES.

The Schedule referred to in these Letters Patent and making part of the same.

I, THOMAS Ross, of Rutland, county of Rutland, and State of Vermont, have invented certain Improvements in Steam and other Enginery, of which the'following is a specification.

My invention consists in hardening the interior valve and valve-seat of cylinders of steam and other engines, by casting them upon'metal chills, thereby rendering them extremely llard and dense, insuring durability, and greatly reducing the friction of the parts.

It consists, further, in the construction of the packing-rings of the piston, by which it is greatly` simpli- Iied in its parts, and rendered more eiiicient in its operation.

To enable others skilled in the art to make and use my invention, I will proceed to describe it, together with my mode of carrying it into effect, reference being had to the drawing accompanying this specication, of whicht A, .in fig. 1, represents a cylinder' of theordinary form of construction, upon which the common slidevalve B is used. .l

The light shading at a a a and b b represents that portion ofthe cylinder casting which is chilled, a a a being the interior or bore ofthe cylinder, and b l), the valve and valve-seat.

I prefer to conne the chilling process to that part of the borev ofthe cylinder and the valve-seats upon which the piston and valve respectively travel, and the working-ta0e of' the valve, leaving the remainder of the casting in its natural condition of softness.

It is necessary that provision be made in the construction of the chill which forms the core for the interior or bore of the cylinder, so as to allow for the This I accomplish in making said chill or core in four parts, some of which are small segments ofthe circle, showing a section of wedge-form, with itsbase toward the center of the core, and being forced inward by the contraction of the cylinder-casting will relieve the whole core.

Itwould, perhaps, be desirable, when casting large cylinders, to have the number of pieces forming this chill increased; or a core-may be used, consisting of a cylinder with a longitudinal opening for asingle wedgeshnped segment, which will be pressed inward by the contraction of the casting.

A steam-engine cylinder thus cast, and of a proper qualit-y of iron, will be much more durable, and the hard surfaces of the working-parts will also greatly reduce the amount of friction iu working In boring such a cylinder, which to many may seem entirely im practicable, itis only necessary to have astrong and rigid apparatus, with cutting-tools of the kind and form usually used for turning chilled rolls, and giving the boring-bar a very low rate of speed, giving the cutting-tool about twelve inches of travel per minute.

In some cases emery-whcels mightvbc advantageously 2. In combination with an engine with chilled working surfaces', as described, a valve, with its working face hardened by chilling, substantially as described.

THOS. ROSS,

Witnesses:

R. BARRETT, C. CLARK. 

